Transplant Site Affects Splenic T- and B-Cell Survival and Function

• We killed control animals and those with intraperitoneal and subcutaneous splenic autotransplants at intervals of up to one year to study gross, microscopic, and immunologic characteristics that might explain previously observed experimental variations in protection against postsplenectomy sepsis. Lymphocyte cell populations were studied qualitatively using concanavalin A (Con A)–and phytohemagglutinin—stimulated tritiated thymidine incorporation, and quantitatively by immunofluorescence assay. Subcutaneous implants showed fibrosis and lost mass, which was reflected in reduced numbers of functional B- and T-cell lymphocytes. Intraperitoneal implants grew during the observation period and demonstrated normal numbers of functional B- and T-cell lymphocytes. Previous experimental results showing protection against postsplenectomy sepsis following intraperitoneal but not subcutaneous autotransplantation may be the result of maintaining normal numbers of functional lymphocytes in the transplanted splenic tissue rather than a qualitative change in cellular function.